Drier having flow rate-responsive control means



DRIER HAVING FLOW RATE-RESPONSIVE CONTROL MEANS Filed Feb. 6, 1961 2 Sheets-Sheet l 63 J0 jg June 1, 1965 c. A. COBB ETAL DRIER HAVING FLOW RATE-RESPONSIVE CONTROL MEANS 2 Sheets-Sheet 2 Filed Feb. 6, 1961 (ONOE/ISER coivTfiaL United States Patent 3,186,106 DRIER HAVING FLOW RATE-REPONSIVE CONTRQL MEANS Clifton A. Cobb and James T. Williams, St. Joseph, Mitch assignors to Whirlpool Corporation, a corporation of Delaware Filed Feb. 6, 1961, Ser. No. 87,160 9 Claims. (CI. 34-45) This invention relates to drying apparatus and in particular to apparatus for drying fabrics and the like subsequent to a cleaning operation.

In the conventional drying apparatuses, means are provided for controlling the duration of the drying operation, which means are conventionally adjustable to permit the user to adjust the drying time as desired. While such control means permit adjustment of the drying cycle, they have a serious disadvantage in that they require the operator to estimate the necessary drying time so that in most cases, the drying cycle is unnecessarily long resulting in overdrying or too short to effect complete drying. The present invention comprehends a new and improved drying apparatus avoiding this problem.

Thus, a principal feature of the present invention is the provision of a new and improved drying apparatus.

Another feature of the invention is the provision of such apparatus including new and improved means for automatically controlling the drying cycle.

A further feature of the invention is the provision of such an apparatus including means automatically discontinuing the drying cycle upon a reduction of the amount of cleaning fluid, remaining in the material being dried, to a preselected value.

Other features and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings wherein:

FIGURE 1 is a diagrammatic vertical section of a dryer apparatus embodying the invention;

FIGURE 2 is an enlarged vertical section of a sensor switch therein;

FIGURE 3 is an enlarged elevation illustrating the housing of the sensor switch; and

FIGURE 4 is a diagram illustrating the electrical circuit of the dryer apparatus.

In the exemplary embodiment of the invention as shown in FIGURE 1, a dryer apparatus generally designated as is shown to comprise a cabinet 11 and a casing 11a. A pylon member 12 rotatably supports a cylinder 12a for rotation within casing 11a to, define a drying chamber 13, access to the drying chamber being provided through a front opening 14 in the cylinder 12a and corresponding front openings 15 and 15a in the cabinet 11 and casing 11a normally closed by a siutable door 16. Air is circulated from the drying chamber 13 by means of air translation means such as a blower 17 through a duct 18 to a condensing chamber 19 defined by an enclosure 20, and from chamber 19 through a duct 21 housing a conventional air heater 22 back to the drying chamber 13 through duct 21a. A suitable electric motor 23 is mounted within the enclosure 11 for driving, through suitable means such as belts 24 and 25, the drying cylinder 12a and blower 17.

Dryer apparatus 10 may be utilized to. dry material such as fabrics and the like which have been subjected to a cleaning fluid such as detergent-containing water or a dry cleaning fluid such as perchlorethylene. In the case of the water type cleaning fluid, the washing cycle would, of course, comprise a rinse cycle wherein the material would be subjected only to clear water. Thus, in this instance, the cleaning fluid would effectively comprise water.

3,186,1fl6 Federated June 1, 1965 The cleaning fluid is vaporized in the drying chamber 13 by the passage of the heated air through chamber 13 as discussed above. The vaporized cleaning fluid passes with the air through blower 17 and duct 18 to condensing chamber 19. A suitable condenser coil 26 is disposed in condensing chamber 19 which, when contacted by the vaporized cleaning fluid, condenses the fluid to liquid form. The condensing coil 2d may be supplied with a cooling medium such as water or low temperature refrigerant as desired, either of which would be controlled by the valve 59. As best seen in FIGURE 1, the lower end of the condensing chamber enclosure defines a frusto-conical collector 27 having an outlet 28 at the bottom thereof communicating through a duct 29 with a sensing chamber 30 defined by a housing 31 in which is received a sensor switch 32. Where the cleaning fluid comprises a reuseable dry cleaning fluid, the apparatus '10 is provided with a duct 33 for conducting the condensed cleaning liquid to a reservoir 34 in the lower portion of enclosure 11 for reuse as desired. Where the cleaning fluid comprises water, the water may be discharged from the sensor chamber 30 to a drain (not shown) as desired. In either case, however, the condensed cleaning liquid is caused to pass in thermal transfer association with the sensor switch 32, the rate of flow of the cleaning liquid therepast being dependent on the amount of cleaning liquid being condensed in chamber 19. The amount of cleaning liquid being condensed in chamber 13, in turn, is dependent on the amount of cleaning liquid remaining in the material being dried in drying chamber 13.

The variable heat transfer provided by the variable rate of flow of cleaning liquid through the sensor chamber 30 is herein utilized to control automatically the duration of the drying cycle of apparatus 10. More specifically, sensor switch 32 comprises a thermoresponsive switch, herein including a fixed contact 35 and a movable contact 36 controlled by a bimetallic disc 37 acting through an actuator pin 38 to engage contact 36 with contact 35 when the temperature sensed by the disc 37 reaches a preselected value. The temperature of the disc 37 is affected by an annular electric heater 39 carried on a suitable annular insulator 40 in an annular chamber 41 circumjacent the disc 37 and defined by a suitable housing member 42 of the switch and a rear housing member 44. Suitable electrical terminals 43 are provided extending through the rear housing member 44 for connection to the heater 39 and to switch contact members 35 and 35. A front plate 45 and underlying gasket 46 defining the front housing members of the switch are provided with a central opening 47 aligned with disc 37 permitting facilitated transfer of heat from the disc 37 through the housing member 42 to cleaning fluid in sensor housing chamber 30. The switch 32 is arranged so that sufficient heat is transferred to the cleaning fluid to prevent the closing of contacts 35436 until such time as the rate of flow of the cleaning fluid against the housing member 42 at opening 47 reaches a preselected minimum value resulting from a substantial completion of the drying operation. It should be understood that the design of the sensor chamber 30 and sensor switch 32 can vary as long as the condensate can carry or direct heat from heater 39 away from the thermoresponsive disc 37.

Referring now more specifically to FIGURE 4 of the drawing, the movable contact 36 of the switch 3-2 is connected to one side of a timer motor 48, the other side of which is connected to one lead L1 of a suitable power supply (not shown). The timer motor drives a plurality of cams 4-9, 50, 51, 52 and 53 on a shaft 54. Timer mot-or 4-8 is further connected to power supply lead L2 through a switch 55 controlled by cam 5th. The heater 39 of switch 32 is connected through a variable resistor 56 to lead L1, and to lead L2 through a switch 57 controlled by cam 49. One side of drive motor 23 is connected to lead L1 and the other side is connected through a switch 58 controlled by cam 51 to the lead L2. A solenoid 59a is provided to operate the valve 59 in the condenser coil 26 and is connected to lead L1, and through a switch 60 controlled by cam 52 to lead L2. The air heater 22 is connected at one side to lead L1, and through a control switch 61 controlled by cam 53 to lead L2. The timer motor 48, cams 49-53, and switches 57- 61 comprise elements of a timer 61 which may be mounted on the upper front portion of the dryer enclosure 11. An operating knob 63 may be associated with the timer 62 for initiating operation thereof.

Reference being had now primarily to FIGURES 1 and 4, the operation of dryer apparatus is initiated by manipulation of operating knob 63 to rotate shaft 54- to close switch 55 thereby energizing timer motor 48. Concurrently, the switches 53 and 61 are closed to energize drive motor 23 and air heater 22. Thus, the cylinder 12 is rotated while, concurrently, heated air is circulated through the drying chamber 13 by the blower 17. The switch 60, however, is open at this time, thus solenoid 59a remains deenergize-d thereby preventing delivery of coolant to the condenser coil 26 and permitting the temperature of the air to rise as rapidly as possible to initiate vaporization of the cleaning fluid from the material being dried. After a preselected period of time such as one minute, the timer motor rotates shaft 54 sufliciently to cause cam 52 to close switch 66 energizing solenoid 59a allowing the condensing medium to pass through the valve 59 and coil 26 to commence condensing of the vaporized cleaning liquid in the condenser chamber 19, Upon further rotation of the shaft 54, cam 50 permits switch 55 to open, thereby deenergizing the timer motor. Concurrently, cam 49 closes switch 57 to energize superficial heater 39 which introduces heat into the chamber 41 which influences the temperature of disc 37. This begins a period of the total dry cycle of variable time as controlled by the switch contacts 35 and 36. At this time, a substantial quantity of condensed cleaning fluid is passing through the sensor chamber 39 against the heat conducting surface of housing member 42 cooling the disc 37 sufficiently to maintain the switch contacts 35 and 36 open notwithstanding the energization of heater 39. As long as suflicient cleaning liquid passes through sensor chamber in heat transfer association with the disc 37, the timer motor remains deenergized.

However, when the cleaning fluid has been substantial-1y fully removed from the material in the drying chamber 13, insufficient condensed fluid is provided to the sensor chamber 30 to prevent disc 37 from moving inwardly with a snap action, as a result of the heating thereof by heater 39, to engage contact 36 with contact 35. Since switch 57 is closed by. cam 49 at this time as earlier explained, a circuit is completed from lead L2 through the contacts and 36 of switch 32 to the timer motor whereby further rotation of shaft 54 is now effected. After a short period of operation of timer motor 48, such as one minute, cam 53 opens switch 61 to deenergize air heater 22 so that unheated air is circulated through the drying chamber, and cam closes switch 55 to energize the timer motor 48 independently of sensor switch 32. At this same time, cam 49 opens switch 57 to deenergize the heater 39 although it would be possible to allow heater 39 to remain energized for the remainder of the drying cycle. Where the cleaning fluid comprises water, this air circulation effects a desirable cooling of the dryer and material therein, and where the cleaning fluid comprises a dry cleaning fluid, this air circulation permits deodorizing of the material. In this latter instance, outside air may be introduced. The timer motor continues to operate through this cool down or deodorizing period for a predetermined time, such as five minutes,

4: until all of the switches 55, 58 and 60 open to end the drying cycle.

The variable resistor 56 permits adjustment of the heating effect of heater 39 whereby control of the dryness of the material being dried in chamber 13 is obtained. Thus, where the material is to be incompletely dried, the resistor 56 would be adjusted to increase the voltage across the heater 39 and thereby cause the bimetallic strip 37 to engage contact 36 with contact 35 while the flow of condensed cleaning fluid through chamber 30 is yet appreciable. The variable resistor 56 also allows the degree of dryness to be controlled to the same point regardless of the installation voltage by controlling the voltage across the heater 39.

Having described our invention as related to the embodiment shown in the accompanying drawings, it is our intention that the invention be not limited by any of the details of description, unless otherwise specified, but rather be construed broadly within its spirit and scope as set out in the accompanying claims.

We claim:

1. In a drier as for use in drying fabrics and the like cleaned by subjection to a cleaning fluid, apparatus comprising: means defining a drying chamber; means for vaporizing cleaning fluid in said drying chamber; means defining a condensing chamber; means for transferring vaporized cleaning fluid from said drying chamber to said condensing chamber; means in said condensing chamber for condensing said vaporized fluid therein; control means including a heater, and thermoresponsive means responsive to heat from said heater for discontinuing operation of the vaporizing means when the thermoresponsive means is heated by said heater to a preselected temperature; and means for flowing condensed fluid from the condensing chamber in heat transfer association with said thermoresponsive means for maintaining the tempera-ture thereof below said preselected temperature during such time as vaporized fluid is being transferred from the drying chamber to the condensing chamber at at least a preselected rate.

'2. In a drier as for use in drying fabrics and the like cleaned by subjection to a cleaning fluid, apparatus comprising: means defining a drying chamber; air heating means for vaporizing cleaning fluid in said drying chamber; means defining a condensing chamber; circulating means for transferring vaporized cleaning fluid from said drying chamber to said condensing chamber; means in said condensing chamber for condensing said vaporized fluid therein; control means including a heater, and thermoresponsive means responsive to heat from said heater for discontinuing operation of the air heating means when the thermoresponsive means is heated by said heater to a preselected temperature; and means for flowing condensed fluid from the condensing chamber into heat transfer association with said thermoresponsive means for maintaining the temperature thereof below said preseleeted temperature during such time as vaporized fluid is being transferred from the drying chamber to the condensing chamber at at least a preselected rate, said control means including mechanism continuing operation of said circulating means a preselected time subsequent to the heating of said thermoresponsive means to said preselected temperature.

3. In a drier as for use in drying fabrics and the like cleaned by subjection to a cleaning fluid, apparatus comprising: means defining a drying chamber; means for vaporizing cleaning fluid in said drying chamber; means defining a condensing chamber; means for transferring vaporized cleaning fluid from said drying chamber to said condensing chamber; means in said condensing chamber for condensing vaporized fluid entering said condensing chamber; control means including a heater, and thermoresponsive means responsive .to heat from said heater for discontinuing operation of the vaporizing means when the thermoresponsive means is heated by said heater to a preselected temperature; means for flowing condensed fluid from the condensing chamber into heat transfer association with said therrnoresponsive means for maintaining the temperature thereof below said preselected temperature during such time as vaporized fluid is being transferred from the drying chamber to the condensing chamher at at least a preselected rate; and means adjustably controlling the rate of heat supplied from said heater to said thermoresponsive means for regulating the condensed fluid flow rate required for actuation of said thermoresponsive means.

4. In a drier as for use in drying fabrics and the like cleaned by subjection to a cleaning fluid, apparatus comprising: means defining a drying chamber; means for vaporizing cleaning fluid in said drying chamber; means defining a condensing chamber; means for transferring vaporized cleaning fluid from said drying chamber to said condensing chamber; means in said condensing chamber for condensing said vaporized fluid therein; control means including a heater, and thermoresponsive means responsive to heat from said heater for discontinuing operation of the vaporizing means when the thermoresponsive means is heated by said heater to a preselected temperature; means for flowing substantially all the condensed fluid from the condensing chamber into heat transfer association with said .thermoresponsive means for maintaining the temperature thereof below said preselected temperature during such time as vaporized fluid is being transferred from the drying chamber to the condensing chamber at at least a preselected rate; and means for collecting said condensed fluid subsequent to the passing thereof in said heat transfer association with the thermoresponsive means.

5. In a drier as for use in drying fabrics and the like cleaned by subjection to a cleaning fluid, apparatus comprising: means defining a drying chamber; means for vaporizing cleaning fluid in said drying chamber; means defining a condensing chamber; means for transferring vaporized cleaning fluid from said drying chamber to said condensing chamber; means in said condensing chamber for condensing said vaporized fluid therein; thermoresponsive means to discontinue operation of said vaporizing means when the temperature thereof is at least a preselected temperature; means for delivering heat to said thermoresponsive means; and means for flowing condensed fluid from the condensing chamber into heat transfer association with said thermoresponsive means for maintaining the temperature thereof below said preselected temperature during such time as vaporized fluid is being transferred from the drying chamber to the condensing chamber at at least a preselected rate.

6. In a drier as for use in drying and deodorizing material such as fabrics and the like cleaned by subjection to perchlorethylene, apparatus comprising: means defining a drying chamber for holding material to be dried and deodorized; means for vaporizing perchlorethylene in said drying chamber; means defining a condensing chamber; means for transferring vaporized perchloroethylene from said drying chamber to said condensing chamber; means in said condensing chamber for condensing said vaporized perchlorethylene therein; control means including a heater and thermoresponsive means responsive to heat from said heater for discontinuing operation of the vaporizing means when the thermoresponsive means is heated by said heater to a preselected temperature; means for flowing condensed perchlorethylene from the condensing chamber in heat transfer association with said thermoresponsive means for maintaining the temperature thereof below said preselected temperature during such time as vaporized perchlorethylene is being transferred from the drying chamber to the condensing chamber at at least a preselected rate; and means passing air through said drying chamber for a preselected period of time subsequent to the reaching of said preselected rate of perchlcrethylene transfer to deodorize the material in'the drying chamber.

'7. A drier for drying cleaning fluid from fabrics and the like comprising, means forming a drying chamber to contain said fabrics, means defining a closed circuit air flow path having an exit from and an entrance into said drying chamber, air translation means in said air flow path for forcing a stream of .air therethro-ugh, a first heater in said air flow path .to heat said air stream to vaporize the cleaning fluid from said fabrics, a condenser in said air flow path to condense vaporized cleaning fluid passing through said condenser, a cleaning fluid outlet leading from said condenser, and control means in said condenser outlet sensitive to the rate of flow of condensed cleaning fluid through said condenser outlet to de energize said first heater when the rate of flow of said condensed cleaning fluid passing through said condenser outlet falls below a predetermined value.

8. The drier as defined in claim 7 in which said con trol means includes a normally open electrical switch, thermoresponsive means to operate said switch, and a second heater effective to raise the temperature of said thermoresponsive means to close said normally open switch and thereby deenergize said first heater when the rate of flow of said condensed cleaning fluid passing through said condenser outlet falls below said predetermined value.

9. The drier as defined in claim 8 in which a variable resistor is electrically connected to said second heater to control the voltage across said second heater to control the closing of said normally open electrical switch by said thermoresponsive means at a preselected rate of flow of said condensed cleaning fluid passing through said condenser outlet.

References Cited by the Examiner UNITED STATES PATENTS 2,166,294 7/39 Hetzer 3477 X 2,304,21 1 12/42 Sparrow. 2,619,566 11/52 Mahoney. 2,654,961 10/53 Manecke 34-45 2,743,533 5/56 Smith 34-45 2,824,278 2/58 Johnston. 2, 895, 230 7/ 5 9 Reiley 34-45 NORMAN YUDKOFF, Primary Examiner.

GEORGE D. MITCHELL, CHARLES OCONNELL,

Examiners. 

7. A DRIER FOR DRYING CLEANING FLUID FROM FABRICS AND THE LIKE COMPRISING, MEANS FORMING A DRYING CHAMBER TO CONTAIN SAID FABRICS, MEANS DEFINING A CLOSED CIRCUIT AIR FLOW PATH HAVING AN EXIT FROM AND AN ENTRANCE INTO SAID DRYING CHAMBER, AIR TRANSLATON MEANS IN SAID AIR FLOW PATH FOR FORCING A STREAM OF AIR THERETHROUGH, A FIRST HEATER IN SAID AIR FLOW PATH TO HEAT SAID AIR STREAM TO VAPORIZE THE CLEANING FLUID FROM SAID FABRICS, A CONDENSER IN SAID AIR FLOW PATH TO CONDENSE VAPORIZED CLEANING FLUID PASSING THROUGH SAID CONDENSER, A CLEANING FLUID OUTLET LEADING FROM SAID CONDENSER, AND CONTROL MEANS IN SAID CONDENSER OUTLET SENSITIVE TO THE RATE OF FLOW OF CONDENSED CLEANING FLUID THROUGH SAID CONDENSER OUTLET TO DEENERGIZE SAID FIRST HEATER WHEN THE RATE OF FLOW OF SAID CONDENSED CLEANING FLUID PASSING THROUGH SAID CONDENSER OUTLETS FALLS BELOW A PREDETERMINED VALUE. 